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(No Model.) 2 Sheets-8heet 1.

A. M. PLUMB. ROCK DRILL.

No. 595,969. ya Patented Deo..21,189'7.

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2 .D. e e h S m e e h s 2 B I M Um L D m 0 MB A a. d 0 M O W No. 595,969. Patented Dec. 21,1891.

' INVENTOR WITNESSES ATTORNEYS.

NITED STATES PATENT, FFICE.

ALBERT M. PLUMB, OF COLORADO SPRINGS, COLORADO, ASSIGNOR TO THE PLUMB ROCK DRILL COMPANY, OF SAME PLACE.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 595,969, dated December 21, 1897.

Application filed March 2,1897. Serial No. 625,773. (No model.)

To all whom it may concern:

Be it known that I, ALBERT M. PLUMB, of Colorado Springs, in the county of El Paso and State of Colorado, have invented a new and useful Improvement in Rock-Drills, of which the following is a full, clear, and exact description.

The object of my invention particularly is to improve upon the construction of the rockdrill for which Letters Patent were granted to me September 29, 1896, No. 568,698, the improvement being such as to render the construction more simple, durable, and economic, and to provide for an effective feed and striking movement for the plunger carrying the drill.

The invention consists in the novel construction and combination of the several parts, as will be hereinafter fully set forth, and pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a longitudinal vertical section through the main portion of the machine. Fig. 2 is a horizontal section taken substantially on the line 2 2 of Fig. 1. Fig. 3 is a transverse section taken substantially on the line 3 3 of Fig. 1. Fig. 4 is a perspective View of a portion of the track on which the body or casing of the machine has movement, and Fig. 5 is a side elevation of the machine and its column-support.

A casin g A is provided,the rear end whereof is cylindrical and the central forward portion whereof is substantially rectangular in crosssection, but in the rectangular portion of the casing a partition a is formed, which divides the main portion of the casing into an upper main compartment A and a lower compartment A as shown in Fig. 1.

The casing is usually constructed in two sections and is provided at its rear end with a cap and at its forward end with a cap 11, while between the center and forward end of the casing at the top a housing 12 is formed, as shown in Fig. 1, and at the rear of the housing at the top of the casing an opening 13 is made, which is covered by a hood 14,

the hood being hinged to the casing and provided with a suitable locking device.

A shaft 15 is journaled in suitable lugs formed at the upper part of the casing. This shaft is a drive-shaft and carries a mutilated gear 16, the gear being so formed as to comprise two oppositely located toothed segments. The shaft is turned by means of a handle 15 or by other desired means. A plunger 13 has end movement in the upper compartment A of the casing. WVithin the casing, near the forward end of the plunger, a cylindrical enlargement 17 is formed, provided with spiral grooves forming ratchetteeth 18 longitudinally of the said enlarged portion of the plunger, as best shown in Fig. 1, and this surface of the plunger may be termed the ratchet-surface.

A dog 19 is hinged through the medium of a pin 20 in the housing 12, and this dog is adapted to enter the spaces between the teeth of the ratchet surface of the plunger, as shown in Fig. 3, being held in engagement with the aforesaid ratchet-surface by means of a spring 21. (Shown in the same figure.) The forward end of the ratchet-surface of the plunger is preferably made straight, but the rear end 22 is given a forward inclination, as shown in Fig. 1. A head 23 is provided for the plunger B near its rear end, and the forward peripheral surface 24 of this head is inclined, to be engaged by inclined surfaces on the segments of the mutilated gear 16.

Circumferential teeth 25 are formed on the plunger between the head 23 and the ratchet: surface 17, as is also shown in Fig. 1, and the rear end of the plunger is reduced in diameter, while on its reduced portion adjacent to the head 23 a collar 26 is loosely mounted, provided with a key 27, adapted to travel in guides formed in the interior surface of the upper compartment of the casing or in slots made in its sides.

A spring 27 is coiled around the reduced rear end of the plunger, having bearing at its rear end against a collar 28, loosely mounted in the rear cylindrical portion of the casing and provided with a key 29, similarly guided to the key in the collar 26. A screw 30 is passed through the collar 28 and between the coils of the spring 27, the said screw being held to turn loosely in the cap 10 and isprovided at its outer end with ahandle 31, whereby it may be turned, changing the compression of the spring upon the plunger and regulating the force of the blow, since the plunger is to be drawn backward, compressing the spring by the segments of the gears 16 meshin g with the teeth on the plunger, and when the mutilated gears are disengaged from the teeth on the plunger the spring 27 acts to force the plunger forward and the drill connected with it to an engagement with the work.

A sleeve 32 is secured in the forward end of the casing around the forward end of the plunger, against which the forward end of the ratchet-surface of the plunger strikes at its outward throw. The sleeve 32 is adapted to constitute a protection for a washer 33, made of rubber or other elastic material, the said washer being located between the sleeve 32 and a bushing 34, which constitutes a journal for the forward end portion of the plunger. A chuck 35 of any approved construction is attached to the forward outer end of the plunger B, the said chuck being adapted to receive a drill 36.

In the lower compartment A of the casing A a lever 37 is fulcrumed by means of a pin 38 at or near the rear end of its lower compartment, the rear portion of the lever being bifurcated, as shown in Fig. 2, but the forward end is in one piece, and between the upper surface of the forward end of the lever and the upper surface of the bifurcated section an inclined surface 39 is formed. (Shown particularly in Fig. 1.)

At the rear of the inclined surface 39 a spring 40 bears upon the under face of the lever 37 and upon a bridge 41, an opening 42 being made at each side of this bridge in the bottom of the casing. Beneath the forward or single section of the lever 37 at each side of the opening 42 blocks 43 are formed, in which the pivot-pins of pawls 44 are located, each of the said pawls being provided with a link 45, pivoted thereto, said links extending up through the single section of the lever 37, having a pin at their upper ends, or equivalent device, to hold them in position. Between the forward portion of the lever 37 and each dog a spring 46 is located and said springs are coiled around the links 45.

The pawls 44 are arranged to engage with teeth 47, formed upon a track-bar 48, which track-bar is provided with channels 49 inits sides,receiving gibs 50, projected downward from the sides of the casing, as shown in Fig. 3, and the side portions of the casing are strengthened by means of ribs 51. The casing is adapted to travel on the track-bar 48, and the teeth 47 are inclined to the horizontal plane of the track at an angle of forty-five degrees, more or less, so that the machine will work in either direction on the track and allow the sets of dogs 44 to act, and likewise ings 42.

a set to be hereinafter described. The trackbar 48 is secured to a bed 51, which bedis pivoted on a column 52 or other form of support, as illustrated in Fig. 5.

At the rear of the pawls 44 a second set of pawls 53 is located, having their pivot-pins located in blocks 54 at the sides of the open- Each pawl 53 is provided with an upwardly-extending arm 55, and at the rear of each arm a pin 56 is located, attached to a shifting rod 57. Springs 58 are coiled around the shifting rod 57, engaging with the rear faces of the arms from the pawls 53 and against the pins 56 on the said rod, as shown in Fig. 1. The shifting rod extends outfroni the lower chamber of the casing at the rear, terminating preferably in a knob 59, while a spring 60, coiled around the shifting rod or bar, engages with the said head and the outer face of the casing, as also shown in Fig. 1. When this rod 57 is pushed forward, the rear set of pawls 53 will be disengaged from the teeth on the track 48.

In operation when the shaft 15 is revolved a segment of the mutilated gear will engage with the inclined surface 24 on the head of the plunger, moving the plunger slightly rearward until the teeth on the segment can mesh with the teeth 25 on the plunger, whereupon the plunger will be carried back as far as determined, compressing the spring 27, and as the plunger moves back the pawl 19', by entering a spiral groove in the ratchetsurface of the plunger, will give to the latter, for example, one-quarter, more or less, of a revolution. When the plunger is released from a segment of the mutilated gear, the spring 27 will act to force the plunger forward and bring the drill in engagement with the surface to be drilled. At the forward movement of the plunger said plunger does not turn, since the dog 19 will jump over about two teeth and will have no action whatever on the ratchet-surface of the plunger. As the plunger is moved backward the inclined rear edge 22 will engage with the inclined surface 39 on the lever 37 and force the lever downward, so that the pawls 44 will be locked in engagement with the teeth on the track, preventing the casing from moving forward, While the pawls 53 at the rear will prevent the casing moving rearward. At the forward movement of the plunger the lever 37 will be released and the pawls 44 will be disengaged from the teeth of therack.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. In a rock drill, the combination with a casing, of a plunger adapted to carry a drill and having end movement in the casing, the plunger having its forward end. enlarged and provided with spiral grooves to form a ratchetsurface, and provided with a head adjacent to the reduced rear end and teeth between the head and ratchet-surface, acollar on the reduced end of the plunger, a second collar in the casing, a screw passing through the end of the casing and engaging said second collars, a spring between the said collar, a mutilated gear comprising oppositely-located toothed segments engaging the head and teeth of the plunger, and a dog pivoted in the casing and normally engaging the ratchet-surface of the I plunger, substantially as described.

2. In a rock-drill, the combination with a track provided with teeth, a casing held to slide upon the track and having an opening in its bottom, and a plunger having end movement in the casing, of a pivoted lever in the casing and having an upwardly-projecting inclined surface between its ends, said inclined surface being adapted to be engaged by the plunger to operate the lever, pawls pivoted in the casing and adapted to engage the teeth of the track, links pivoted to the pawls and projecting through the lever and provided with stops at their ends, and springs coiled on the links between the pawls and the lever, substantially as described.

3. In a rock-drill, the combination with a track provided with teeth, a casing held to slide upon the track and having an opening in its bottom, and a plunger having end movement in the casing, of a pivoted lever in the casing and having an upwardly-projecting inclined surface adapted to be engaged by the plunger, pawls pivoted in the casing and connected with said lever, a second set of oppositely-arranged pawls pivoted in the casing and having upwardly-projecting arms,a shifting rod loosely connected with the arms of the pawls and extending out through the casing, and springs on the shifting rod between the pawls and stops on said rod, substantially as described.

at. In a rock-drill, the combination with a track provided with teeth, a casing held to slide on the track and having an opening in its bottom, and a plunger having end movement in the casing, of a pivoted lever having one end bifurcated and formed with an inclined surface at the juncture of the bifurcated portion with the single portion, pawls pivoted in the casing and adapted to engage the teeth of the track, links pivoted to the pawls and projecting through the lever and provided with stops at their ends, springs surrounding the links, a second set of oppositely-arranged pawls pivoted in the casing and provided with upwardly-projecting apertured arms, a shifting rod projecting through the arms of the said pawls and extending out through the casing, said shifting rod being provided with laterally-projecting stops, one on each side of the arms of the pawls and one between the said pawls, and springs on the rod between the stops and the pawl-arms,substantially as herein shown and described. ALBERT M. PLUMB.

Witnesses:

J. O. PLUMB, CHAS. PEARSON. 

